Railway traffic controlling apparatus



Nov. 9, 1937. H. A. WALLACE 2,098,638

' RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed July 29, 1926 2 Sheets-Sheet l .27/ J Bell 264 263 257 256 252 246 23/ INVENTOR Original Filed July 29, 1926 2 Sheets-Sheet 2 III) U INVENTOR'.

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Patented Nov. 9, 1937 UNITED STATES PATENT ()FFICE RAILWAY TRAFFIC CONTROLLING APPARATUS Herbert A. Wallace, Edgewood Borough, Pa., as-

signor to The Union Switch & Signal Company, Swissvale, Pa, a. corporation of Pennsylvania Application July 29, 1926, Serial No. 125,659 Renewed September 11, 1930 112 Claims.

are diagrammatic views, which when placed end to end with Fig. 1 on the left, illustrate one form of railway traffic controlling apparatus embodying my invention.

Referring to the drawings, the reference characters a and b designate two stretches of railway track over which tramc at times moves in both directions. The tracks a and b are connected by a track switch F, operated by a power actuated mechanism or switch machine which I will describe hereinafter, so that when the switch is in its normal position, in which it is illustrated in the drawings, traffic can move without interference along track a. When switch F is reversed, however, traffic is permitted to move from track b into track a, or vice versa. The track rails and i of track a are divided by means of insulated joints 2, into a plurality of track sections AB, B-C, CD, etc., track section AB containing the switch F. By means of other insulated joints 2 that portion of track 2) adjacent the switch F is insulated from the rest of the track to form a track section EF, and the rails of this section are connected directly with the corresponding rails of section AB so that the rails of the sections of both tracks a and b which contain the switch F, are connected in parallel, and these sections will be referred 'to hereinafter collectively as the detector track section or as the switch track section.

. Each track section of track a is provided with a track relay designated by the reference character R with a suitable distinguishing exponent and connected across the rails adjacent one end of the corresponding section. Track circuit ourrent is supplied to the rails of each section by a battery designated by the reference character 01 and connected across the rails adjacent the opposite end of such section. As has been stated, the rails of section E-F are connected in parallel with the rails of section A--B so that a train occupying any portion of the switch track section will shunt the relay R The reference character M designates an auxiliary relay which is arranged to be energized only when the track relays R and R are energized, the circuit for this relay passing from a suitable source of energy such as a battery U through wire 3, front contact 4 of relay R wire 5, front contact 5 of relay R wire I, winding 7 of relay M, and common wire 8 back to battery U Relay M is therefore de-energized when a train occupies either section B-C or section CD. These two sections will be referred to hereinafter collectively as the approach section or as the approach zone, and relay M, since it becomes deenergized when a train approaches within a predetermined distance of switch F, will be referred to as the approach relay.

East bound trafiic, that is, trafiic moving from left to right over track a when switch F is normal, is governed by a home signal S which as here shown is of the semaphore type and comprises a main blade 9 and a separate call-on blade ill. Eastbound traffic moving from track I) to track a when switch F is reversed is governed by a signal S located at point E. Westbound tramc, that is, traffic moving from right to left over track a, when switch F is normal, is governed by a home signal S located at point B and comprising a main blade 9 and a call-0n blade i0. Signals S and S thus constitute a pair of opposing signals governing traffic moving in opposite directions over switch F when it occupies its normal position. The blade ll] of signal S also serves as the opposing signal for signal S so that this blade together with signal S constitutes a pair of opposing signals governing trafllc moving over switch F reversed. Each blade of each of the signals S S and S is controlled by an electroresponsive mechanism, as indicated diagrammatically on the drawings by wires leading to the signal blade, these wires being included in an energizing circuit for the signal mechanism which is governed by means which will be described in detail hereinafter. The reference character S designates an automatic signal located at point C and capable of displaying 2. proceed, a caution, or a stop indication, in accordance with traffic conditions in advance of the signal. Signal S is the usual approach signal, and is controlled by means forming no part of my present invention, and omitted from the drawings for the sake of simplicity.

The mechanisms for actuating the switch F and all of the signals which are shown on Fig. 2 except signal S are actuated by a series of manually controlled electroresponsive devices here shown as polarized direct current relays each designated by the reference character K with a suitable distinguishing exponent. Relay K controls the track switch F, relay K controls the main signals for governing train movements in accordance with trafiic conditions, relay K controls the call-on signals, while relay K is employed to put the signals to stop and to release the switch locking, as hereinafter described. The control relays K are operated by a series of pole-changers G G and G located at a distant control point such as in the office of the train dispatcher. The reference character H designates a clockwork time release of usual and well known form comprising a normally closed contact II and two other contacts comprising a pole-changer G When the time release H is operated contact H is opened and the polechanger G is reversed. When the time release H is released, a time interval elapses before the pole-changer G returns to its normal position and contact closes.

Located also in the control office are a plurality of manually operable levers or push buttons J J J and J each comprising two normally open contacts l2 and I3 and a normally closed contact !4. As will be described in detail hereinafter, the control relays K each respond to a different magnitude of current and they are selectively energized over the same line circuit by single brief impulses of current each of a distinctive character identified by its magnitude and polarity in accordance with the operation of the pole-changers G and the push buttons J.

Associated with the polarized switch control relay K are two selector relays UN and L a. Two similar selector relays L2N and L2H. are associated with the main signal control relay K and relays L and L a are associated with the callon signal control relay K A single selector relay L 1. is associated with control relay K.

The switch machine for the track switch F comprises an operating mechanism including a motor having an armature 83 and a field winding 31. When current of one polarity is supplied to the motor, the switch is moved to the normal position and when the polarity of the current supplied to the armature is reversed, the switch is moved to. its reverse position. A number of contacts is controlled by the switch operating motor in accordance with the position of the switch so that contact 64--6556 is closed at all times except when the switch is in its extreme reverse position and contact 61-65-458 is closed at all times except when the switch is in its extreme normal position. Contacts 203-264205 and contacts 20'|-204206 are closed when the switch occupies its normal or its reverse position respectively, I

The reference characters Q Q Q and Q designate four direct current transmitting relays which are controlled as will be described hereinafter.

Four polarized direct current indication relays each designated by the reference character N with an'appropriate distinguishing exponent are located in the control ofiice as shown on Fig. 1 and associated with each relay N is a polarized repeater relay designated by the reference character T with a distinguishing exponent. The relays N are similar to the relays K hereinbefore referred to and they are controlled over the 6|, through common wire 8 to battery U same pair of line wires as the relays K by single brief impulses of current of distinctive magnitude and polarity which are delivered to the line wires by the operation of the apparatus at the remote station. The repeater relays T control indicators as will be described hereinafter to apprise the operator of the condition of the apparatus.

I will assume that all polarized relays are so arranged that when the relays are energized in the normal direction their polarized contacts are swung to the left and that when the relays are energized in the reverse direction their polarized contacts are swung to the right. Polarized direct current relays of the usual type are so arranged that when the relay is de-energized the polarized armature remains in the position to which it was last moved.

Having thus described in general the arrangement and location of the various constituent parts comprising my invention, I will now proceed to explain the operation of the apparatus.

As here shown the track is unoccupied, switch F occupies its normal position, signal S indicates caution and all of the remaining signals indicate stop. I will first assume that the operator wishes to reverse switch F to permit traffic to proceed along the track b. To accomplish this result, he reverses pole-changer G and operates push button J Current then flows from a suitable source of energy such as a battery U through wires I5 and I6, contact |2 of push button J pole-changer G wire contact ll of device H, wires 8, I9 and 20, front contact 2| of relay M, wire 22, front contact 23 of relay Q wire 24, back contact 25 of relay Q wire 26, back contact 21 of relay Q wires 28 and 29, front contact 39 of relay Q wire 3|, front contact 32 of relay R wire 33, winding of relay K wire 34, winding of relay K wire 35, winding of relay K wire 36, winding of relay K wires 31, 38 and 39, resistances 40, 4| and 42, wire 43, pole-changer G contact 3 of push button J and wires 44 and 45, back to battery U It will be clear that current supplied over the circuit just traced traverses the windings of relays K K K and K in series. These relays are constructed in such manner that they require progressively larger currents to cause the relays to become energized, relay K becoming energized with the smallest value of current, and relay K requiring the largest current, The circuit just traced for these relays includes resistances 40, 4| and 42, in series and the current supplied to the relays K over this circuit is sufficient to energize relay K but is not suflicient to energize relays K K or K With the pole-changer Gr reversed, the polarity of the current supplied to the circuit is such that relay K becomes energized in the reverse direction.

When relay K closes its reverse contact 58, relay L R, is picked up by current which flows from battery U through wires 46, 41, and 48, back contact 49 of relay K wires 50 and 5|, back contact 52 of relay K wire 53, back contact 54 of relay K wire 55, front contact 56 of relay K wire 51, reverse contact 58 of relay K wires 59 and 69, winding of relay L a, and wire The closing of front contact 12 of relay L a completes a stick circuit for this relay from battery U through wires 46, 62, and 63, contacts 64-65-66, wire 69, back contact 10 of relay L N, wire 1|, front contact 12 of relay L a, wires 13 and 60, winding of relay L a and wire 6| back to battery U through common wire 8. The operator may then restore the push button J to its normal position, terminating the impulse of current supplied to relays K and allowing relay K to drop.- The pick-up circuit for relay L a is thereby opened but the relay is subsequently maintained in its energized condition over its stick circuit, so as to store the switch operating impulse until the switch is operated to its reverse position in correspondence with the energized condition of relay L 3. When relay L n picks up, the closing of front contact 8| completes a circuit for the switch operating mechanism and current fiows from battery U through wire '14, front contact 15 of relay L4H, wire H5, front contact 11 of relay R wire 18, front contact 8! of relay L B, wire 82, armature 83, wire 84, back contact of relay L N, wire 86, field winding 81, and common wire 8 back to battery U Negative terminal of battery, U is constantly connected with a positive terminal of battery U so that when the circuit just traced is closed, the total voltage of batteries U and U is applied to the armature and field of the switch operating motor. Current supplied under these conditions to the motor is of such polarity that switch F is moved to the reverse position. When the switch has attained its full reverse position, contact 546556 opens, thereby interrupting the circuit for relay L 3 and allowing this relay to release. When this happens, the opening of front contact 8| of relay L a interrupts the operating circuit for the switch mechanism and de-energizes the motor.

I will now assume that the operator wishes to restore switch F to its normal msition. To do this he restores pole changer G to its normal position, in which it is illustrated in the drawings, and operates push button J Current from battery U then flows through wires l5 and it, contact l2 of push button J pole changer G wire 43, resistances 52, ii and 46, through relays K K K and K front contact 32 of relay R front contact 39 of relay Q back contact 2? of relay Q back contact 25 of relay Q front contact 23 of relay Q front contact 2! of relay M,

and contact ll of device H as before, and back through pole-changer G contact l3 of push button J and wires Mi and 45, back to battery U It will be noted that the circuit for relays K which is closed when push button J is operated and pole-changer G is normal, is the same as hereinbefore traced when push button J is operated with pole-changer G reversed except that current flows through the circuit in opposite direction. When thiscircuit is closed, therefore, only relay K picks up and the polarity of the current is such that this relay closes its normal contact. Current from battery U then flows through wires 48, 4'! and 48, back contact 49 of relay K wires 59 and El, back contact 52 of relay K Wire 53, back contact 55 of relay K wire 55, front contact 55 of relay K wire 5?, normal contact 55 of relay K wires 88 and 89, winding of relay L N and common wire 3 back to battery U Relay L N therefore becomes energized and completes a stick circuit over which current flows from battery U through wires 55, 62 and 63, contact 68i55-51, wire 258, back contact 12 of relay L R, wire H, front contact Ill of relay L N, wires 98 and 89, winding of relay UN, and common wire 8 back to battery U The operator then restores push button J to its normal position, interrupting the circuit for relay K and permitting this relay to release. The pick-up circuit for relay L n is thereby interrupted, but the relay remains energized until the switch returns to its normal position in correspondence with the energized condition of relay L because current is now supplied to the relay over its stick circuit. When relay L N becomes energized, current flows from battery U through wire 15, front contact '55 of relay L n, wire 16,,

front contact 'ii of relay R wires 78 and 88, front contact 85 of relay L 11, wire 35, armature 33, wire 82, back contact 83 of relay L n, wires 9! and 86, field winding 8? and common wire 5?,back-to battery U The combined voltage of batteries U and U is therefore applied to armature 83 and field winding 8? of the switch operating motor. The current then supplied to the motor is of such polarity that the motor returns the switch F to its normal position. When the switch attains its extreme normal position, contact 63- tit-t? opens, interrupting the stick circuit for relay L N and permitting the relay to release. The opening of front contact 85 of this relay interrupts the supply of current to the switch operthat he has operated pole-changer G and the,

push button 5 to pick up relay L p. and that the switch is being driven from its normal to its reverse position, and that before the stroke of the switch completed he restores pole-changer G to its normal position and operates J Relay K then becomes energized in the normal direction, energizing relay L N. The opening of back contact ill of this relay breaks the stick circuit for relay Us and allows that relay to drop. The stick circuit for relay UN is then closed from contact E2 of relay Us and the apparatus then operates to restore the switch to its normal position as will be clearly understood from the foregoing explanation.

Certain of the signals S are controlled in part by a circuit controller designated by the reference character P and operating in accordance with the position of the switch F. Contacts l33l38, lit-i28 and l58l58 are closed only when the switch occupies its normal position, and contacts lee-tea i2il l2ii and its-45S are closed only when the switch occupies its reverse position.

In explaining the operation of the signal control circuits, I will first assume that the switch F occupies its normal position to permit the movement of trafiic along track a and that the operator wishes to clear blade 9 of signal S to permit eastbound traffic to proceed along the track a. To accomplish this result he operates push button J with pole-changer G in its normal position. A circuit is then closed over which current fiows from battery U through wires l5 and 92, push button 5 pole-changer G resistances ti and 4t, and thence through relays K in series over the same circuit previously traced for these relays, returning through contact H of device H, wire ll, pole-changer G push button J and wires 33 and 35, back to battery U It will be noted that current supplied to the relays K over this circuit flows through resistances it and ill. The parts are so proportioned that current supplied under these conditions is of sufficient magnitude to pick up both relays K and K and since pole-changer G is in the normal position the polarity of this current is such that relays K and K become energized in the normal direction. Normal contact 58 of relay K is therefore closed but the pick-up circuit for relay L is open at back contact 54' of relay K which relay is now energized. Relay L therefore remains deenergized. The closing of front contact 54 of relay K completes a pick-up circuit for relay L2H and current flows from battery U through wires 46, 41, and 48, back contact 49 of relay K wires and 5|, back contact 52 of relay K wire 53, front contact 54 of relay K wire 94, back contact 95 of relay L3N, wire 96, back contact 91 of relay L 3, wire 98, normal contact 99 of relay K wires I00 and IOI, winding of relay L mwires I02 and I03, front contact I04 of relay R and common wire 8 back to battery U The closing of front contact I01 of relay L completes a stick circuit for this relay, current flowing from battery U through wires 46', 41 and 48, back contact 49 of relay K wires 50, E and I06, front contact I01 of relay L N, wires I08 and I0I, winding of relay L N, wires I02 and H33,

front contact I04 of relay R and common wire 8 back to battery U The operator may then restore push button J to its normal position, interrupting the circuit for relays K and K These relays therefore release but relay LZN remains in its energized condition by virtue of its stick circuit. With relay LZN energized, blade 9 of signal S is cleared, current flowing from battery U through wires 14, M19 and H0, front .contact III of relay L N, wires H2, H3, H4, H5,

I I6, H1 and H8, operating mechanism of blade 9 of signal 8*, wire I59, contact I20I20"- of circuit controller P, wire I 21, front contact I22 of relay LZN, wire I23, back contact I24 of relay L n, and wires I25, I26, I21, I28, I29, 41, and

46, back to battery U Signal S therefore indicates proceed to permit an eastbound train to proceed over the track a. I will assume that when the push button J was operated to pick up relay LZN, switch F was in the reverse position. Under these conditions it would be safe to permit eastbound traffic from track b to proceed through the stretch but it would be unsafe to clearblade 9 of signal S to permit traflic to proceed along track a from left to right. When the switch is in the reverse position, contact I20---I20 is open and contact mil-420 is closed so that when the relay L N becomes energized, signal S is cleared, instead of blade 9 of signal the circuit for signal S passing from battery U through wires 14, I99 and H0, front contact III of relay LZN, wires H2, H3, H4, and I30, operating mechanism of signal S wires I3I and I32, contact I2 l---I2El of circuit controller P, wire I2I, front contact I22 of relay LFN, wire I23, back contact I24 of relay L 12, and wires I25, I26, I21, I28, I29, 41, and 46, back to battery U It therefore follows that when relay L N'is energized, a signal of one pair or the other is cleared for eastbound traffic through the stretch of track shown in the drawgization of the switch selecting relays and must be; up to effect the energization of a signal selecting relay.

If the operator wishes to permit westbound traffic to pass the switch he reverses pole-changer G and operates push button J Current is therefore supplied to the relays K in series as explained in connection with the operation of push button J when pole-changer G is normal. Relays-K and K therefore pick up but relays K 'and K remain deenergized, the polarity of current supplied to the relays being such that relays K and K are energized in the reverse direction. Since back contact 54 of relay K is open, relay L p, does not become energized but a pick-up circuit is completed for relay L a over reverse contact 99 of relay K which circuit is similar to the pick-up circuit already closed for relay UN and will be readily understood from the drawings without tracing the circuit in detail. When relay L R becomes energized, the closing of front contact I33 thereon completes a stick circuit for this relay so that the relay is subse quently maintained in its energized condition independently of its pick-up circuit. The operator may then restore the push button J 2 to its original position, thereby de-energizing relays K and K without opening relay LZR.

If switch F is normal, the energization of relay L2H, completes a circuit from battery U through wires 14, I99 and H0, front contact I55 of relay L 11, wires II2, I34, I35 and I36, operating mechanism of blade 9 of signal S wire I31, contact I38-I38 of circuit controller P, wire I39, front contact I24 of relay L2H. wire I23, back Contact I22 of relay LZN, and wires I25, I26, I21, I28, I29, 41, and 46 back to battery U When this circuit is closed, blade 9 of signal S is cleared to permit trafiic to proceed along track a past the switch F.

If switch F is reversed when relay L a picks up, current flows from battery U through wires 14, I39 and H0, front contact I55 of relay L 11, wires II2, I34, I35, I40 and MI, operating mechanism of blade I0 of signal S wires I42 and I43, contact I3ii'--I38 of circuit controller P, wire I39, front contact I24 of relay L 3, wire I23, back contact I22 of relay LZN, wires I25, I26, I21, I28,

I29, 41, and 46 back to battery U When this circuit is closed, therefore, blade I0 of signal S is cleared. It is therefore plain that the "callon blade I9 is used also for a low speed signal for permitting westbound traflic to proceed from track a totrack' b through the switch F.

It will be noticed that the circuits for each of the relays L and IPR include a front contact I04 of track relay R but this relay is de-energized when a train occupies any portion 'of the switch track circuit. It follows that relays UN and HR can be energized only when this track section is unoccupied. The signal operating circuits thus far described can therefore be completed to clear the corresponding signals only when the switch track circuit is unoccupied, and if one of the signals is cleared and a train enters the switch track circuit the signal will return immediately to stop, because of the consequent de-energization of relays L2N or LZR. Under certain conditions, however, it may be desirable to clear one of the signals when the switch track circuit is already occupied by a train. For ex ample, it may occur that an eastbound train has passed signal S and the operator wishes to permit a following train to enter section A-B past signal S The operator may permit this movement of traific by clearing the call-on blade I0 of signal S To accomplish this result he operates push button J with pole-changer G normal. Current then flows from battery U through push button J pole-changer G and resistance to relays K in series and back over pole-changer G and push button J to battery U The circuit over which this current flows through the relays K is so similar to similar circuits already traced that it is deemed unnecessary to trace the circuit in detail. It should be noted that current thus supplied to the relays K flows only through resistance 40 and not through resistances 42 and 4]. The parts are so proportioned that under these conditions, relays K K and K pick up and the polarity of the current is such that these relays become energized in the normal direction. The pick-up circuits for relays L and L2N are open at back contact 52 of relay K so that these relays remain de-energized but since relay K; is now energized, a pick-up circuit is closed for relay L3N from battery U through wires 46, 41 and 48, back contact 49 of relay K wires 50 and 5!, front contact 52 of relay K wire I44, back contact I of relay L N, wire I46, back contact I41 of relay L n, wire I48, normal contact 549 of relay K wires I and I5I, winding of relay L3N, and common wire 6 back to battery U It will be seen that this circuit does not include a front contact of relay R and relay L therefore picks up even though relay R is de-energized. The closing of relay L completes a stick circuit for the relay over which current flows from battery U through wires 46, 41 and 48, back contact 49 of relay K wires 50, I05 and I52, front contact I53 of relay L N, wires I54 and l5I, winding of relay L3N and common wire 8 to battery U The operator may then restore push button J to its original position, thereby de-e'nergizing relays K K and K but relay L3N remains in its energized condition by virtue of its stick circuit just traced. With relay L closed the call-on blade ill of signal S is cleared, the circuit for this blade passing from battery U through wires 14 and I09, front contact I56 of relay L N, wires II2, I I3, I I4, H5, H6, H1, and HM, operating mechanism of blade II) of signal S wire I51, contact I50I58 of circuit controller P, wire I59, front contact I60 of relay L3N, wire I6I, back contact I62 of relay L3H, and wires I63, I26, I21, I28, I29, 41, and 46, back to battery U It will therefore be plain that the operator, by proper manipulation of push button J 3 and. pole-changer G may clear the call-on blade of signal S to permit a train to enter the switch track section even though this section is already occupied so that it is impossible to clear the main blade 9 of signal 3-.

If the switch F is in its reverse position when relay LBN picks up, the operating circuit for the call-on blade I0 of signal S is open at front contact I58-I58 of circuit controller P and call-on blade of signal S cannot be cleared. Current can flow however, from battery U through wires 14 and I09, front contact I56 of relay L3N, wires H2, H3, H4, and I30, operating mechanism of signal S wires I3! and I64, contact I5BI58 of circuit controller P, wire I59, front contact I60 of relay L H, wire I6I, back contact I62 of relay L 12 and Wires l63, I26, I28, I29, 41, and 46 back to battery U When switch F is reversed, therefore, if relay L N picks up, signal S clears to permit movement of eastbound trafiic over track 19/, past the signal, even though the switch track section is already occupied by a train.

In similar manner if the push button J 3 is operated with pole-changer G reversed, current is supplied to the relays K in series through resistance 40, and relays K K and K pick up, but relay K remains de-energized. The polarity of the current then supplied to the relays is such that the relays close their reverse contacts. A pick-up circuit is therefore closed for relay L R similar to the pick-up circuit just traced for relay LSN. This pick-up circuit does not include a front contact of relay R and therefore relay L3H. becomes energized, even though relay R is deenergized due to the presence of a train in the switch track section. When front contact I65 of relay L 11 closes, a stick circuit is completed for this relay similar to the stick circuit hereinbefore traced for relay LBN. The operator may then restore push button J to its original position, de-

energizing relays K K and K-', but relay L R remains picked up over its stick circuit. With relay L a energized, current flows from battery U through wires 14 and I09, front contact I66 of relay L R, wires II2, I34, I35, I40, and MI, operating mechanism of call-on blade I0 of signal S wires I42 and I 61, front contact I62 of relay L a, wire I6I, back contact I60 of relay L3N, and wires I63, I26, I21, I29, I29, 41, and 46 back to battery U It therefore follows that the energization of relay 113R clears the call-on blade of signal S irrespective of the position of switch F so that when the push button J is operated with polechanger G reversed to clear the blade I0 of signal S eastbound trafilc is allowed to pass signal S even though the switch track section is already occupied by a train which de-energiz es relay R and makes it impossible to clear the main blade 9 of signal S It will be seen from the foregoing that the energizing circuits for the signals are so interlocked as to prevent the clearing of two opposing signals at the same time. Thus, for example, the circuit for blade 9 of signal S as hereinbefore traced includes front contact I22 of relay LZN, the connecting wire I23, and back contact I24 of relay L 12, while the energizing circuit for blade 9 of the opposing signal S includes back contact I22 and front contact I24, and furthermore, the circuits for signal S and blade I0 of signal S which control traffic movements over switch F reversed are similarly controlled over contacts I60 and I62 of relays L and L3H. In addition, the two pairs of stick relays L are interlocked so that only one stick relay can be picked up at a time, because the pickup circuit for each relay of a pair includes back contacts of both relays of the other pair and the pickup circuits for the two relays of the same pair include opposite polar contacts of the same control relay K. Finally, the interlocked circuits include contacts of the switch circuit controller P which are responsive to the operation of the switch control relay K so that the clearing of a signal is prevented even though the signal control means is operated, unless the switch is in,

the proper position to permit the clearing of the signal selected by the signal control relay which is energized.

It will be noted that the circuits for relays L2N, 112R, UN, and L 3 all include a back contact 49 of relay K If, therefore, the operator has energized any of these relays L to clear a corresponding trackway signal and wishes to restore that signal to stop, he may do so by energizing relay K This may be accomplished by operatbattery .U

ing push button J Iwill assume that the time release H occupies its normal position in which it is'illustrated in the drawings when the push button J is operated. Current then flows from battery U through push button J and the polechanger G of device H, to relays K in series and back through the pole-changer G and push button J to battery U over a'circuit which is similar to other circuits previously traced for relays K. It will be noted that when this circuit .isclosed none of the resistances 42, M, or 49 is interposed in series with the relays. voltages of battery U is therefore applied to re- The full lays K and all of these relays become energized. With device H in its normal position, the polarity of this current is such that the relays K become energized in their normal directions. Circuits for relays L N, 112R, L3N, and L a are all opened at .back contact 49 of relay K so that if any of these relays were energized prior to operation of the ,push button J that relay now becomes de-energized, thereby interrupting the operating circuit .operated by signal S wire I15, circuit controller I16 operated by blade 90f signal S wire I11, circuit controller .I18 operated by blade ID of signal S Wire I19, back contact I89 of relay L n, wire I8I, back contact I82 of relay UR, wire .I83, back contact- I84 of relay L3N, wire l85, back contact I86 of relay L mwire I81, winding of relay L a, wires I88,. I89, I90 and200, front contact 2M of relay M and common wire 8 back to The circuit just traced is provided with a branch which passes from wire I89,

"through wire I93,.back contact I94 of-track relayR and common wire 8 back to battery U Another branchis provided for the pick up circult of relay L 11, from wire I88, through wire .I96, reverse contact I91 of relay K wire I98, front contact I99 .of relay K and back to common wire 8 to the battery U Still another branch. is provided for the circuit for relay L 11,

from wire I90, through wire I9I, front contact I92 of relay L 3 and back through common wire '8 to battery U It will be seen that this branch last traced comprises a stick circuit for relay L43 which is closed only after the relayhas already become energized by current over some other branch of its circuit. Under normal conditions, the approach relay M is energized, the track relays R and B being normally energized, and if all the signal relays are deenergized and the signals are at stop relay HR is energized over the circuit first traced for this relay including front contact 2DI of relay M. The stick circuit for relay HR is also closed, so that relay LR will remain energized if a train occupies section CD, and relay M becomes de-energizecl.

However, when signal S indicates proceed or any of the other signals is cleared, relay L 11 becomes de-energized. It will be apparent that relay L R will becomereenergized when a train enters the detector section and the signal is put to-stop automatically due to the closing of back contact I94 of track relay R and will also be- .come reenergized when a signal is manually put pied so that front contact 20I closed. When relay Us is de-energized front contact 15 is open, and the circuit for the switch operating mechanism is therefore interrupted. It

to stop, provided the approach section is unoccuof relay M is follows that relay L R serves as an approach locking relay, and that when relay HR is de-energized, the apparatus provides a condition analogous to the Well known approach locking which prevents operation of the switch if a signal ,in'that case he operates the clockwork time release H to reverse pole-changer G He then operates the push button J*, to energize relay K andthen allows the clockwork time release to return to its original position. Due to the slow return characteristics of the device H, a considerable interval of time elapses before the polechanger G} returns to its normal position. If

push button J is operated when the pole-changer is reversed, current is supplied through the push button J and the pole-changer G to relays K in series over a circuit which is similar to that previously described for these relays when pole changer G is normal and push button J is operated, the only difference being that when G is reversed the current supplied to relays K is of such polarity that the relays become energized in the reverse direction. Relay 114R, therefore picks up and closes its stick circuit including its own front contact I92. The closing of front contact 15 of relay L a again permits the circuit to be closed for the switch operating mechanism in response to an operation of relay L N or L a, provided the switch section is unoccupied so that contact 11 of the detector track relay R is closed.

It should be observed however, that the switch remains locked and the signals are held at stop during the time interval required for the device H to return to its normal position, after relay L 3 has been energized, because the checking contact II of this device is open and under this condition it is impossible to operate any of the selecting relays L by manipulation of the push buttons J J or J because thecircuit for relays K which is closed by the operation of these push buttons includes the normal contact II of device H. If the device H and push button J are operated to energize relay L 12 when section 13-6 rangement, as similar circuits could be arranged for providing approach locking for eastbound traffic in the same manner as here provided for westbound trafiic.

As suggested hereinbefore, I have provided indication means arranged to inform the operator concerning the condition of the trackway governing devices controlled by the pole-changers G and push buttons J. For example, two visual indicators 22% and 23I, here shown as electric lamps having illuminated covers G and R, are lighted when the switch track section is unoccupied or occupied, respectively. Other indicators give the operator further information concerning the condition of the apparatus as will appear from the following description.

Relay R is a two-position relay and is normally energized when the switch track section is unoccupied has been explained. Relay Q is a slow pick up and slow release repeating relay which is controlled by front contact H34 of relay R and is therefore energized when relay R is picked up. In explaining the return indi cation of the condition of the switch track section, I will first assume that a train enters the section, thereby tie-energizing relay R The opening of front contact lfi i of relay R deenergizes relay Q but due to the slow releasing characteristics of the latter relay a time interval elapses during which relay R is released and relay Q is picked up. During this brief interval an indication circuit is closed over which current flows from battery U through wires 2H), 2H, and 22?, back contact 228 of relay R wire 252, front contact 2I3 of relay Q wires 2M, ZIE and 38, thence through contact M of each push button J and the winding of each relay N to wire it, and through wire 26, front contact 25 of relay lvi, wire 22, front contact 23 of relay Q wire 2 back contact 25 of relay Q wire 26, back contact 2i" of relay Q wires 28 and 2A6, front contact Ell of relay Q wire M8, back contact 2E9 of relay R and wires 2% and 2% back to battery U When this circuit is closed, the full voltage of battery U is applied to relays N N N and N in series and these relays N are constructed similar to relays K to require currents of diiferent magnitudes to energize the relays. When the circuit just traced is closed, however, relays N all become energized and the polarity of the current supplied to the relays is such that they close their reverse contacts. With relay N energized in the reverse direction, front contact 222 is closed and the reverse contacts and 22 are also closed so that relay T is energized in the reverse direction by current from battery U over circuits which will be obvious from the drawings. Lamp 226 is therefore lighted to indicate that the switch track section is occupied. As soon as the time interval required for operation of relay Q elapses, this relay drops, thereby interrupting the circuit over which relay N was energized but relay '1 maintains its reverse contact closed and lamp 225 is constantly energized.

If, now, relay R becomes energized, as when the train leaves the switch track section, a time interval elapses before relay Q closes its front contacts and during this time interval relay R is picked up and relay Q is released. During this brief interval, current from battery U flows over front contact 223 of relay R and back contact 2I'l of relay Q through relays N in series, over a circuit similar to that just traced for these relays. It will be seen that the full voltage of battery U is applied to relays N but the polarity of the current flowing in the relays is such that they are energized in their normal direction. Relay N being energized in the normal direction, relay T is also picked up in the normal direction so that lamp 23! is lighted to indicate that the switch track section is unoccupied. After a brief interval, relay Q picks up,

thereby interrupting the circuit for relays N but the normal contacts of relay T remain closed so that lamp 22I remains lighted.

Located in the control office are two lamps 246 and 252 provided with visual indicators N and R which are lighted when the switch F occupies its normal or reverse position, respectively. In explaining the control of lamps 24s and 252, I will first assume that relay L 3 is energized, thereby completing the circuit for the armature 83 and field winding 87 of the switch operating motor, and that the switch is being moved from its normal to its reverse position. For a brief interval, near the end of the transit of the switch, a circuit is closed for relay Q from battery U through wires 46, 41, 529, I28, I2'I, and 232, winding of relay Q wire 233, contact 28l2E--2ilfi, wire 234, front contact 235 of relay L a and common wire 8 back to battery U Relay Q is therefore energized and the current supplied to this relay over the circuit just traced is of such polarity that the relay becomes energized in the reverse direction. When this happens a circuit is closed from battery U through wires 2 I B, 2 I i, and 23%, front contact 23'! of relay Q wire 238, reverse contact 239 of relay Q wires 2%, 2 E 5, and 38, thence through contact i l of each push button J and the winding of each relay N in series and back through wires I9 and 2e and 242, resistance 243, reverse contact 25I of relay Q wire 2&8, front contact 249 of relay Q and wires 2%, and HI back to battery U It will be manifest that when the circuit just traced is closed, current is supplied from battery U to relays N in series, through resistance 243. The relays are so proportioned that under these conditions, relays N N and N pick up in the reverse direction but relay N remains de-energized. With relay N energized in the reverse direction, relay T also becomes energized in the reverse direction, thereby lighting lamp 245 to indicate that the switch has moved to its reverse position. Of course front contact 235 of relay L R opens as soon as this relay releases at the end of the transit of the switch, as has been explained in detail hereinbefore, but relay T having once been energized in the reverse direction, holds its reverse contact closed so that lamp 246 remains lighted.

In similar fashion when relay L 1; is energized and the switch is being returned to its normal position, a temporary circuit is closed for relay Q from battery U through wire 54, front contact '55 of relay L411, wire it, front contact ll of relay R wires l3, as and I9, front contact 247 of relay L N, wire 248, contact 2i5-2!l l--2Il3, wire 233, winding of relay Q and wires 232, I27, I28, I29, M, and (it, back to battery U Relay Q therefore becomes energized in the normal direction for a brief interval and duringthis interval, current from battery U flows through resistance 243 to relays N in series over a circuit Which is similar to that traced above for reverse energization of relay Q Relays N N and N therefore become energized in the normal directions and relay T also picks up in the normal direction, thereby lighting lamp 252 to indicate that the switch has been restored to its normal position.

The operator is informed concerning the signal positions by means of the signal indicators 25'! and here shown as lamps having illuminated covers carrying representations of signals in the stop and proceed positions, respectively. In explaining the control of the indicators 256 and 251, I will first assume that the operator has taken the proper steps to clear one of the trackway signals. For purposes of explanation I will assume that apparatus.

relay L 3 has been energized to clear main blade 9 of signal S As the signal blade approaches its clear position a contact 253253= controlled by the signal blade is closed for a brief interval. During this interval, a circuit is closed for relay Q from battery U through wires 14, I09, and I I0, front contact I of relay LZR, Wires H2 and i34, contact 253 2i3 operated by signals S wires 254 and 255, winding of relay Q wires l28, I29, 4'! and 46, back to battery U Relay Q therefore becomes energized in the reverse direction for a brief interval of time and during this interval an indication circuit is closed, supplying current from battery U through resistances 243 and 244 to relays N in series. This indication circuit is so similar to the circuits controlled by relay Q that it is deemed unnecessary to trace the circuit in detail. When this circuit is closed, however, relays N and N become energized in the reverse direction so that relay T also becomes energized in the reverse direction, thereby lighting indicator 256 to inform the dispatcher that blade 9 of signal S has cleared. Of course the indication circuit controlled by relay N is closed only While this relay is energized, but relay T holds its reverse con tact closed so that the indicator 256 remains lighted.

It will be observed that the circuit just traced for relay Q included front contact E55 of relay L R, but in parallel with this contact are front contact I i I of relay LZN, front contact ififi of relay L3N and front contact I66 of relay L313. It therefore follows that when the operator has energized any of these relays to clear corresponding signals the indicator 256 apprises him of the fact that the signal has actually moved to the clear position.

Returning to the assumption that relay 112R is energized and that blade 9 of signal S has cleared, I will assume that the signal is returned to its stop position by ole-energizing the relay L 3. As the blade approaches its stop position, a contact 253253 is closed for a brief interval and during this interval current flows from battery U through wires 46, 41, I29 and I28, wind ing of relay Q wires 255 and 254, contact 253-453 operated by signal S wire 214, back contact 265 of relay L N, back contact 266 of relay L2H, wire 261, back contact 268' of relay LZN, back contact 269 of relay L 3 and common wire 8 back to battery U Relay Q then becomes energized in the normal direction and dur ing the interval that this relay is thus energized, current from battery U flows through resistances 243 and 244 and relays N in series in such direction that relays N and N are energized in the normal direction. Relay T therefore picks up in its normal direction, lighting indicator 251 to inform the despatcher that the signal has returned to its stop position.

The lamps 264 and 263 inform the operator concerning the condition of the approach locking These lamps are controlled partly by relay Q which is a slow-acting relay controlled by front contact 273 of relay M in such manner that when relay M'is energized, relay Q is also energized. In explaining the operation of the approach indication, I will first assume that relay M becomes'de-energized as by the entrance of a train into section CD. This relay therefore opens, but relay Q due to its slow-releasing characteristics, holds its front contacts closed for a brief interval of time. During this time interval, current from battery U flows over wires 2| 0, 2| I, 236, back contact 26! of relay M and front contact 260 of relay Q wires 240, M5 and 38,

thence through relays N in series over circuits which are similar to the circuits controlled by re lays R and Q for indicating the condition of the switch track section. When this circuit is closed, resistances 243, 244, and 245 are all included in series with the relays N and the parts are so proportioned that under these conditions, relay N becomes energized in the reverse direction, but the remaining relays N do not pick up. Relay T therefore picks up in the reverse direction. When relay T becomes energized, a single stroke bell 253 is operated by current supplied from battery U over front contact 2' of relay T thereby calling the attention of the operator to a change in the condition of the approach locking apparatus. When the relay is energized in the reverse direction, lamp 263 is lighted to indicate that the approach section is occupied. When the approach section is vacated, relay M becomes energized, but relay Q does not close its front contact for a time interval and during this interval, current from battery U is supplied to relays N, through resistances 243, 244, and 245, over front contact 26! of relay M and back contact 26!! of relay Q The current thus supplied to relays N picks up only relay N in the normal direction, thereby energizing relay T in the normal direction and lighting lamp 264. It should be pointed out that while I have, in the apparatus here shown and described, accomplished the variations in current strength supplied to relays K and relays N by means of resistances of different values interposed in series with these relays, this particular arrangement is not essential and any other means could be used for varying the strength of the current through the relays. It should also be pointed out that my invention is not limited to the control of the particular railway governing devices illustrated in this application, but that any other suitable governing devices could be controlled from the despatchers oilice in similar manner.

Although I have herein shown and described only one form of railway traffic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, a plurality of trafiic governing devices for said 7 stretch separately controlled from a distant point,

a plurality of polarized relays located at such point and requiring currents of different magnitudes to energize the relays, a source of energy for supplying current to all said relays, means controlled by said traific governing devices for controlling the polarity and magnitude of the current supplied to said relays, and a plurality of indicators located at such distant point and selectively controlled by said relays.

2. In combination with a single pair of line wires, a group of relays normally connected with said wires, a second group of relays normally connected with said line wires, manually operable means for at times supplying current to said line wires for selectively operating the relays of the second group, and means controlled by the relays of such second group for at times supplying current to said line wires for selectively operating the relays of said first group.

3. In combination a plurality of relays connected in an electrical circuit, means for at times removing certain of said relays from said circuit and for supplying current to the circuit at such times for selectively operating the remaining relays, and means controlled by such remaining relays for at times supplying current to said circuit for selectively operating said certain relays.

4. In combination with a trafiic governing device a first relay for controlling said device, means including a single pair of line wires for controlling said relay from a distant point, a plurality of other relays normally connected with said line wires at such distant point, means controlled by said device and by trafiic conditions adjacent said device for at times supplying current to said line wires for selectively operating said other relays, indication means selectively controlled by such other relays, and means for disconnecting said other relays from the line wires when current is being supplied to the line wires for controlling said first relay.

5. In combination, a streach of railway track, a track relay responsive to traffic conditions in said stretch, a trafiic governing device for said stretch, means including a single pair of line wires for controlling said device from a distant point, a polarized relay at times connected with said line wires adjacent such distant point, and means controlled by said track relay for supplying said line wires with current of one polarity or the other according as a train enters or leaves said stretch.

6. In combination, a stretch of railway track, a track relay responsive to traific conditions in said stretch, a traflic governing device for said stretch, means including a single pair of line wires for controlling said device from a distant point, a polarized relay at times connected with said line wires adjacent such distant point, a slow acting relay controlled by said track relay, and means controlled by said track relay and by said slow acting relay for supplying said line wires with current of one polarity or the other according as a train enters or leaves said stretch.

7. In combination a plurality of trafilc governing devices, means including a single pair of line wires for selectively controlling said devices from a distant point, a plurality of relays located at such distant point and selectively responsive to the character of the current supplied thereto, means for normally connecting each of said relays with said line wires, and means effective upon an operation of any of said devices to supply said line wires with current of a different character depending upon the device which is operated.

8. In combination, a plurality of traflic governing devices, means for selectively controlling said devices from a distant point over a single pair of line wires, a first group of relays located at such distant point and selectively responsive to the character of the current supplied thereto, means for normally connecting each relay of said first group with said line wires, a second group of relays selectively controlled in accordance with the condition of said devices, and means controlled by each relay of said second group for at times supplying the line wires with current of a different character for selectively operating the relays of said first group.

9. In combination, a railway traflic governing device, control means for moving said device to one position or the other controlled from a distant point over a single pair of line wires, a signal adjacent said device, locking means effective if said signal is manually put to' stop when a train is approaching within a predetermined distance of said device to render said control means.

ineffective, and means manually controlled over said line wires and effective when the signal is at stop for rendering said locking means ineffective.

10. In combination, a railway traffic governing device, means for moving said device to one position or the other controlled from a distant point over a single pair of line wires, a signal adjacent said device, a contact arranged when open to prevent the controlof said device from said distant point, means effective to open said contact when the signal is cleared and to maintain it open if the signal is put to stop when a train is approaching within a predetermined distance of said device, and means located at said distant point for subsequently closing said contact over said line wires.

11. In combination with a railway track switch, control means for moving said switch to its normal or its reverse position controlled from a distant point over a single pair of line wires, a

signal governing the movement of traflic over the switch, locking means rendered effective when the signal is cleared and remaining effective if the signal is manually put to stop when a train is approaching within a predetermined distance of said switch to render said controlmeans ineffective, means for manually controlling said signal, and other means controlled from said distant point over said line wires and effective at the expiration of a time interval following an operation of such other means after said signal has been put to stop to render said locking means ineffective.

12. In combination with a railway track switch, a relay adjacent said switch and controlled from a distant point, means controlled by said relay for operating said switch, a signal governing the movement of traffic over the switch, locking means rendered effective when the signal is cleared and remaining effective if the signal is manually put to stop when a train is approaching within a predetermined distance of" said switch to prevent the control of said switch by said relay, means for manually controlling said signal, other means controlled from said distant point for rendering said locking means ineffective, and means operating for a time interval after actuation of said other means to prevent operation of said relay from said distantpoint.

13. In combination with a railway switch, a

first and a second relay selectively controlled from a point remote from the switch, a normally energized relay arranged to be deenergized when a train is approaching said switch, a fourth relay having a circuit including a front contact of said normally energized relay, a branch around said front contact including a contact of said second relay, and means controlled by said first relay and effective when said fourth relay is energized to operate said switch. 7

14. In combination with a plurality of traiiic governing devices, a first group of relays for separately controlling said devices and requiring currents of different characters to operate the relays, means controlled from a distant point for at times supplying currents of different characters to all said relays over a single pair of line wires, a second group of relays selectively controlled by said devices and by traific conditions said devices, a third group of relays norrnaily connected with said line wires at 3 saidi distantwpoint and :requiring currents ofdif- -ferent: characters wtow operate the relays, and means contrclled by the relays of the second :group for at times supplyingsaid, line wires with currents; of different. characters to selectively control the 'relays of the third group.

'15.. In combination, a stretch of railway track,

a track relay -responsiveto traflic conditions in said stretch, a-traflicgoverning device for said stretch, meanswincluding a single pairof line wiressfor controlling said device from a distant point, a relay controlled by said track relay, and i means *controlled,-,by said last mentioned relay andsaid track relay for supplying-said line wires with current of onempolarity. or theother acw cording as a train enters or leaves said stretch.

i 16; Incombination with a single setof line y wires, 9; .first: group of relays normally .connected first group, athird group of relays, means controlled by the relays of said first group for momentarily energizing the relays of said third group, means included insaid third group for continuing each relay in .its last operated position, indicating means controlled by the relays of said, third group, a fourth group of relays normally energized by said second group, means included insaid fourth group for continuing each relay in its last operated-position, and traffic controlling devices controlled by the relays of said fourth group.

17. In combination, a plurality of relays connected in an electrical circuit, means for at times removing certain of said relays from said circuit and for momentarily supplying current to the circuit at such times for selectively operatingthe remaining relays, and means controlled by such remaining relays for at times supplying 'current to said circuit for selectively operating said certain relays.

18.In combination, an ofiice and a station connected by a single line circuit, means at the oflice 'for supplying a single brief impulse of -energy of a distinctive character to said line circuit, a traffic governing device at said station,

- means responsive to said single impulse to initiate movement-of: said: device and to complete such movement after the termination of said impulse, and indication means at-said ofiicecontrolled over rwsaid line circuit and responsive to traflic conditions adjacent said station.

'19; In combinatioman office and a station con- .nected by a single line circuit, means located at the-office for supplying said line circuit with 60' stick relay at the station, means responsive toan 3 impulse of a predetermined character in said brief current'impulses of diiierent characters, a

line circuit for energizing saidstick relay, means for subsequently holding said stick relay'energized after the termination of said impulse, a traflic governing device at said station controlled by said stick relay, and indication means at the oflice controlled over said iine circuit in accordance with traflic conditions adjacent said station.

20. In= combination, an office and a station con- .-nected by a single line circuit, means located at the ofiice for supplying said -1ine circuit with brief current impulses of different charaeters, a stick relay at the Station, means responsive toan impulse of a. predetermined character in -said line circuit for energizing said stick relay, meansfor subsequently holding said stick relay energized after the termination of said impulse, a traffic governing device at said station controlled by said stick relay, and indication means at the oflice controlled over said line circuit in accordance with the condition of said device.

21. In combination, an ofiice and a station connected by a single line circuit, a relay located at said station and connected in saidoircuit, means at the oflice for at times supplying current'impulses to said circuit for controlling said linerelay, a stick relay at said station, means effective upon a singlaoperation of said line relay in response to a current impulse in said line circuit to energize said stick relay, means for subsequently holding said stick relay energized after the termination of said impulse, transmitting means at said station for at times supplying indication current tosaid line circuit, means at conditions adjacent said station for at times supplying, a; single indication impulse to saidline circuit, indication means at the office responsive to said indication impulse in-the line circuit to display a distinctive indication which 'persists .after the terminationof said indication impulse,

transmitting means at theoflice for at times supplying current to said line circuit for controlling said device, and apparatus for prevent- ,ing said indication means from responding to current supplied to said line circuit =by'said transa .mitting means.

i 23. Incombinationwith an office and a station connected by alinecircuit, an ofiice relay and a station relay normally connected in said circuit,

means at .the oflice for at times removing said, .oflice relay from said circuit and supplying a control current impulse to the line circuit for operating said station relay, a trafiic governing device. at the station, means responsive to an .operation of. said station relay for initiating a control ot/said device and .for continuing such control after the termination of said control impulse, means .at thestationfor at times removing saidstation relay from said circuit and supplying anzindication current impulseto said circuit for operating said office relay, and means at the office .for displaying a-distinctive indication in response to operation of said office relay and for continuing such indication after the termination of said indication impulse.

24. Inscombination, an ofiice and a station connected by a line circuit, an 'ofiice relay nor- .mally, connected in said circuit, means at said station for Supplying. only a single impulse of .currenttosaid line circuit to operate said office relay, an indication device, and a second relay controlled by said office relay and operating in response to an energization of said ofiice relay .by said single impulse to produce persistent operation of said device after the termination of said impulse.

25.. ,In-combination, anofiice and a station connected by. aline circuit, a plurality of traflic governing devices at said station, means responsive, to..a change in the-condition of any said device to characteristically and momentarily control said line circuit, means at the office selectively responsive to such control of the line circuit to display a distinctive indication, and means for continuing such indication after the termination of the control which caused it.

26. In combination, an ofiice and a station connected by a line circuit, a first group of relays at the oflice all included in said circuit and selectively responsive to the character of the current supplied thereto, a second group of relays selectively controlled by the relays of said first group, indication means selectively controlled by the relays of said second group, and means at said station for supplying said line circuit with current impulses of different characters.

27. In combination, an ofiice and a station connected by a line circuit, means at the station for momentarily and characteristically controlling said line circuit in accordance with trailic conditions adjacent such station, and means at the office selectively responsive to such momentary control of the line circuit to display a continuous indication.

28. In combination, an office and a station connected by a line circuit, a traffic governing device at said station, means responsive to a change in the condition of said device to momentarily and characteristically control said line circuit, and means at the ofiice selectively responsive to such momentary control of the line circuit to display a continuous indication.

29. In combination, an office and a station connected by a line circuit, a plurality of traffic governing devices at the station, means responsive to a change in the condition of any said device to impose upon said circuit a momentary control, the character of which depends upon the particular device and its condition, and means at the office selectively responsive to such momentary control of the line circuit to display continuous indications.

30. In combination, an oflice and a station connected by a line circuit, a section of railway track located at said station, trafilc governing devices adjacent said section, means located at said office for controlling said devices over said line circuit, means responsive to the approach of a train to said section to momentarily control said line circuit, and means at said office responsive to such momentary control of said line circuit to give a continuous approach indication.

31. In combination, an office and a station connected by a line circuit, a section of railway track located at said station, traffic governing devices adjacent said section, means located at said ofiice for controlling said devices over said line circuit, locking means at said station for at times modifying the control of said devices by said ofiice means in accordance with trafiic conditions, and means controlled over said line circuit for continuously indicating the condition of said looking means at said omcc.

32. In combination, an office and a station connected by a line circuit, a section of railway track located at said station, two signals for governing traffic over said section, means at the office for imposing distinctive momentary controls upon said line circuit, means at the station responsive to one such momentary control of the line circuit to clear one of said signals and hold such one signal clear provided said section is unoccupied, and means also at the station and responsive to another momentary control of the line circuit to clear the other said signal and hold such other signalclear independent of the condition of the track circuit.

33. In combination, an electrical device responsive to the polarity of current supp-lied thereto, a plurality of electroresponsive devices including said electrical device, a manually operable device, means controlled by said manually operable device for controlling the energization of said electl'oresponsive devices successively and of said electrical device by current of a given polarity, a second manually operable device, and means controlled by said second manually operable device independently of said first manually operable device for energizing said electrical device by current of the opposite polarity.

34. In combination, an electrical device responsive to the polarity of current supplied thereto, a plurality of electroresponsive devices including said electrical device, a manually operable device, means controlled by said manually operable device ior controlling the energization of said electroresponsive devices successively and of said electrical device by current of a given polarity, and means controlled independently of said manually operable device for energizing said electrical device by current of the opposite polarity.

35. In combination, a plurality of electroresponsive devices, a manually operable device, a second manually operable device, a stick relay, a pick-up circuit for said stick relay controlled by said first manually operable device, a stick circuit for said stick relay controlled by said second manually operable device, and means controlled by said stick relay for energizing said electroresponsive devices successively.

36. In combination, a plurality of partly interinclusive groups of electroresponsive devices, a manually operable device for each of said groups, asecond manually operable device for each of said groups, a stick relay for each of said groups, a pick-up circuit for each of said stick relays controlled by the said first manually operable device for the same group, a stick circuit for each of said stick relays controlled by the said second manually operable device for the same group, and means controlled by each of said stick relays for energizing the electrorcsponsive devices in its group successively.

37. In combination with a railway track switch, a signal for governing traffic over said switch, a relay for controlling said signal, and a locking circuit including in series a back contact of said relay and a contact operated by said signal and closed when said signal is at stop for controlling said switch.

38. In combination, a stretch of railway track, a signal for governing traiiic movements over said stretch, control means for said signal, a stick relay controlled by said signal control means and by traffic conditions, a second signal for goving trafiic movements over said stretch, and means controlled by said stick relay for controlling said second signal.

39. In combination, a stretch of railway track, a signal for governing traific movements in a given direction over said stretch, a second signal for governing traiiic movements in a second direction over said stretch, a control relay for said first signal, a time releasing device, a time releasing contact controlled by said device and which at times becomes closed upon the lapse of a measured period of time after the beginning of an operation of said device, a stick relay, a pick-up circuit for said stick relay including a contact operated by said control relay and a contact controlled ill by'said first signal and also including a'contact controlled by said time releasing device, a stick circuit for said stick relay including a contact operated by said control relay and a contact controlled by said first signal, and means controlled by said stick relay and by said time releasing contact for controlling said second signal.

40. In a train dispatching'system of the signal indicating type, the combination with a single line circuit and associated apparatus for controlling a distant wayside signal and indicating at the'dispatchers oflice the passage of a train by such signal, and means for distinctively indicating over the same line circuit the approach of a train toward said signal when such train is approaching the next signal in the rear of such signal.

41. A train dispatching system of the wayside signal indicating typecoznprising, a distant track switch, a power operated switch machine for operating said track switch, a control relay for controlling said switch machine; a simple line circuit for controlling said control relay from a local source of current at a local dispatchers oillce, an approach relay and an energizing circuit therefor extending a considerable distance along the track for locking said switch maclnne against operation by said control relay if there is a train approaching within said distance, and means including said approach relay for indicating'at said tower the approach of a train toward said switch machine at said considerable distance.

'42. In combination with a railway switch, two control relays each arranged when energized to operate said switch to a different position; manually controlled means for energizing a selected one of said relays from. a remote point, an indication relay controlled jointly by said switch andby both said relays, an'dindication means at said remote point controlled by said indication relay.

43. In combination with a railway switch, two control relays arranged when energized to operate said switch to different positions, manually controlled means for energizing a selected one of said relays from a remote point, a polarized indication relay, means for energizing said indication relay in one direction when one of 'said relays is energized provided the switch occupied a corresponding position, means for energizing the indication relay in the opposite direction provided the switch occupies a corresponding position, and indication means at said remote point controlled by said indication relay,

44. In an approach locking system, a track switch, a control relay, which if de-energized prevents power operation of said track switch, a detector track relay, an approach relay, and an energizing circuit for said control relay including a back contact of the detector track relay and a front contact of said approach relay.

45. In combination, a stretch of railway track divided into a switch section and an approach section, a track switch in said switch section, a

f detector relay and an approach relay controlled by traflic conditions in said switch section and said approach section respectively, a control relay which if deenergized prevents operation of said switch, and a circuit for said control relay controlled by a back contact of said detector relay and by a front contact of said approach relay.

46. In combination with a railway switch, four signals for governing trafiic over said switch, a polarized switch control relay, means for operating said switch to one position or the other acaccesses cording as said polarized relay is energized in one direction or the other, a polarized signal con trol relay, means effective when said signal relay becomes energized in one direction or the other, for selectively clearing one of said signals in accordance with the positions of said signal control relay and of said switch, and manually operable means including a single line circuit for selectively energizing either said switch control relay or said signal control relay from a remote point.

47. In combination with a stretch of railway track having two opposing signals including one at each end of said stretch for governing traffic through said stretch, a manually controlled stick relayfor each signal, and interlocked energizing circuits for said signals, the circuit for each signal including a front contact of the stick relay associated with the signal and a back contact of the stick relay associated with the opposing signal.

48. In combination with a stretch of railway track having two opposing signals including one at each end of said stretch for governing traific through said stretch, a pair of manually controlled relays, and interlocked energizing circuits for each of said signals; the circuit for the first signal including a front contact of the first relay of the pair, a connecting wire, a back contact of the second relay, and a source of energy; and the circuit for the second signal including a front contact of the second relay, said wire, a back contact of the first relay and a source of energy.

49. In combination with a stretch of railway track having two opposing signals including one at each end of said stretch for governing trailic through said stretch, a manually controlled stick relay for each signal, interlocked energizing circuits for said signals, the circuit'for each signal including a front contact of the stick relay associated with the signal and a back contact of the stick relay associated with the opposing signal, and means for preventing either of said signal circuits from becoming closed when said stretch is occupied by a train.

50. In combination with a stretch of railway track having two opposing signals including one at each end of said stretch for governing trafiic through said stretch, a stick relay for each signal, interlocked energizing circuits for said signals,

the circuit for each signal including a front contact of the stick relay associated with the signal anda back contact of the stick relay associated with the opposing signal, manually controlled means for selectively energizing said stick relays,

and means rendered effective when a train enters said stretch for releasing said stick relays.

51. In combination with a stretch of railway track having two opposing signals including one at each end of said stretch for governing traffic through said stretch, a stick relay for each signal, interlocked energizing circuits for said signals, the circuit for each signal including a front contact of the stick relay associated with the signal and a back contact of the stick relay associated with the opposing signal, a track relay for said stretch, a manually controlled pick-up circuit for each stick relay, and holding circuits for said stick relays each including a front contact of said track relay.

52. In combination with a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing traffic through said stretch when the switch is normal and another pair for governing traffic through said stretch when the switch is reversed, two pairs of stick relays including a pair of relays for each pair of signals, interlocked circuits for said relays arranged to prevent the energization of either relay of a pair when a relay of the other pair is energized, an energizing circuit for each signal including a front contact of the associated relay, and manually operable means for selectively closing the circuits for said relays.

53. In combination with a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair, for governing trafific through said stretch when the switch is normal and another pair for governing trafiic through said stretch when the switch is reversed, a manually controlled stick relay for each signal, and an energizing circuit for each signal closed only when the corresponding stick relay is energized and the other stick relay of the same pair is deenergized.

54. In combination with 'a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing trafiic through said stretch when the switch is normal and the other pair for governing trafilc through said stretch when the switch is reversed, a stick relay for each signal, a manually controlled pick-up circuit for each stick relay, a stick circuit for each stick relay, and an operating circuit for each signal closed only when the corresponding stick relay is energized and the other stick relay of the same pair is deenergized.

55. In combination with a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing traffic through said stretch when the switch is normal and another pair for governing traific through said stretch when the switch is reversed, a manually controlled stick relay for each signal, an energizing circuit for each signal closed only when the corresponding stick relay is energized, and electric interlocking means for preventing the energization of more than one of said stick relays at a time.

56. In combination with a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing traffic through said stretch when the switch is normal and another pair for governing trafiic through said stretch when the switch is reversed, a manually controlled stick relay for each signal, an energizing circuit for each signal closed only when the corresponding stick relay is energized, and electric interlocking means independent of said switch for preventing the circuits for more than one of said signals from being energized at a time.

'7. In combination with a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing trafiic through said stretch when the switch is normal and another pair for governing trafiic through said stretch when the switch is reversed, two pairs of stick relays including a relay for each signal, interlocked operating circuits for said signals, the circuit for each signal including a front contact of the stick relayiorsaid signal and .a back contact of the stick. relay for the opposing signal of the pair, and manually operable means for selectively energizing said relays.

58. In combination with a stretch of railway track including a track switch and having two 5 pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing traiiic through said stretch when the switch is normal and another pair for governing traffic through said stretch when the switch is reversed, two pairs of stick relays including a relay for each signal, interlocked circuits for relays and signals arranged to prevent the energization of either relay of a pair when a relay of the other pair is energized and to prevent the 15 energizaticn of either signal of a pair when the relay for the opposing signal is energized, manually operable means for selectively energizing said relays, and means for closing the circuit of each signal when the associated relay is energized.

59. In combination with a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing traffic through said stretch when the switch is normal and another pair for governing traffic through said stretch when the switch is reversed, switch control means governed manually from a. distant point for operating said switch, signal control means governed manually irom a distant point for selectively clearing said signals, and interlocked circuits controlled through the medium of said switch control means for preventing the clearing of a signal except when the route indicated by said signal control means is in agreement with the route indicated by said switch control means.

60. In combination with a stretch of railway track including a track switch and having two pairs of opposing signals each pair including a signal at each end of said stretch, one pair for governing traflic through said stretch when the switch is normal and another pair for governing trafiic through said stretch when the switch is reversed, switch control means governed manually from a distant point for operating said switch, signal control means governed manually from a distant point for selectively clearing said signals, and interlocked circuits controlled by said switch control means through the medium of said switch for preventing the clearing of a signal except when the route indicated by said signal control means agrees with the route determined by the position of the switch.

61. In combination with a stretch of railway track including a track switch and having a pair of opposing signals including one at each end of said stretch for governing traffic over said stretch when the switch is normal, and a second pair of opposing signals including one at each end of said stretch for governing traffic over said stretch when the switch is reversed, two polarized signal control relays manually controllable from a remote point including one for each pair of signals, operating circuits for one signal of each pair including .a neutral front contact and one polar contact of the associated relay, operating circuits for the other signal of g each pair including a neutral front contact and the opposite polar contact of the associated relay, and means for selectively operating said relays.

62. In combination with a stretch of railway track including a track switch and having a pair of opposing signals including one at each end of said stretch for governing traffic over said stretch when the switch is normal, and a second pair of opposing signals including one at each end of said stretch for governing trafiic over said stretch when the switch is reversed, two polarized signal control relays manually operable from a remote point including one for each pair of signals, operating circuits for onesignal of each pair, including a neutral front contact and one polar contact of the associated relay, operating circuits for the other signals of each pair including a neutral front contact and the opposite polar contact of the associated relay, means for selectively operating said relays, means governed manually from a remote point for controlling said switch, and means controlled by said switch control means through the medium of said switch for preventing the clearing of a signal except when the route established by said signal control relays agrees with the route permitted by said switch.

63. In combination with a stretch of railway track including a track switch and having a pair of opposing signals including one at each end of said stretch for governing traffic over said stretch when the switch is normal, and a second'pair of opposing signals including one at each end of said stretch for governing trafhc over said stretch when the switch is reversed, two polarized signal control relays manually operable from a remote point including one for each pair of signals, operating circuits for one signal of each pair including a neutral front contact and one polar contact of the associated relay, operating circuits for the other signals of each pair including a neutral front contact and the opposite polar contact of the associated relay, means for selectively operating said relays, and meanscontrolled by said switch for preventing the clearing of a signal except when the route established by said signal control'relays agrees with the route permitted by said switch.

64. In combination with a detector section of railway track including a track switch, a signal governing the movement'of traffic through said section, an approach track section traversed by traffic approaching said signal, a stick relay adapted to be energized only when said signal indicates stop, selecting means controlled from a distant point for operating the switch, means for preventing operation of the switch by said selecting means except when said stick relay is energized and the detector section is unoccupied, a pick-up circuit for the stick relay closed only when the detector sectionis occupied, a second pick-up circuit for said stick relay closed only when the approach track section is unoccupied, a third pick-up circuit for said stick relay, a slow-acting device adapted to consume a time interval in moving from a reverse to a normal position, means requiring said device to be in its normal position to clear said signal, and a contact included in the third pick-up circuit for said stick relay closed only when said slow-acting device is in its reverse position.

65. In combination "with a railway switch, a signal governing traffic over the switch, selecting means manually controlled from a distant point for operating the switch and the signal,

a slow-acting device, locking means effective at times to prevent an operation of the switch after the signal changes from a proceed to a stop indication, means controlled by said slow-acting device when operated to release said locking means, and checking means controlled by said slow-acting device for'preventing the operation of the signal from a stop to a proceed indication until'said slow-acting device has been restored to its normal position.

66. In combination with a railway switch, a signal governing traffic over the switch, an approach locking relay adapted to be energized only when the signal indicates stop, selecting means controlled from a distant point for clearing the signal and for also operating the switch provided the approach locking relay is energized, a slow-acting device adapted to consume a time interval when operated, means for picking up the approach locking relay when the signal is put to stop provided no train is approaching within a predetermined distance of said signal, means for picking up said approach locking relay when the signal is put to stop and said slowacting device is operated, and checking means controlled by said slow-acting device for preventing the operation of said selecting means except when said slow-acting device occupies its normal position.

' 67. In combination with a detector section of railway track including a track switch, a signal governing the movement of trafiie through said section, means for manually governing said signal, an approach track section traversed by traffic approaching said signal, a stick relay adapted to be energized only when said signal indicates stop, selecting means controlled from a distant point for operating the switch, means for preventing operation of the switch by said selecting means except when said stick relay is energized and the detector section is unoccupied, a pick-up circuit for the stick relay closed only when the detector section is occupied, a second pick-up circuit iorsaid stick relay closed only when the approach track section is unoccupied, a slow-acting device adapted to consume a time interval when operated, a third pick-up circuit for said stick relay closed when said slow-acting device is in its reverse position, and checking means controlled by said slow-acting device for preventing the operation of said signal to cause it to display a proceed indication except when said slow-acting device occupies its normal position.

68. In combination with a detector section of railway track including a track switch, a signal governing the movement of traffic through said section, and an approach track section traversed by traffic approaching said signal, a stick relay adapted to beenergized only when said signal indicates stop, selecting means controlled from a distant point for operating the switch, means for preventing operation of the switch by said selecting means except when said stick relay is energized and the detector section is unoccupied, a pick-up circuit for the stick relay closed only-when the detector section is occupied, a second pick-up circuit for said stick relay closed only when the approach track section is unoccupied, a manually operable releasing device having a normal and a reverse position, a third pick-up circuit for said stick relay closed only when said device is in its reverse position, and checking means for preventing the operation of said signal to cause it to display a proceed indication except -when'said slow-acting device occupies its normal position.

69. In combinationwith a section of railway track, a signal for governing traflic over said sectionga track relay for said section, two stick relays, a holding circuit for each stick relay one such circuit but not the other including a front stick relays, and means for selectively energizing said signal in accordance with the condition of said stick relays.

70. In combination with a section of railway track, a signal for governing traflic over said section, a track relay for said section, two stick relays, a holding circuit for each stick relay one such circuit but not the other including a front contact of said track relay, means controlled from a distant point for selectively energizing said stick relays, and means for manually controlling said signal through the medium of said stick relays, whereby said signal may optionally be controlled by a stick relay responsive to the movement of a train past said signal, or by a stick relay independent of trafiic conditions adjacent said signal.

71. In combination, a section of railway track, a signal governing trafiic through said section, two stick relays, manually operable means controlled from a distant point for selectively energizing said stick relays, a stick circuit for each stick relay, means for causing the signal to indicate proceed when either of said stick relays is energized,'and means for automatically opening the stick circuit for one stick relay but not the other when a train enters said section.

72. In combination with a section of railway track, a signal for governing trailic over said section, a track relay for said section, a manually controlled stick relay, means for energizing said signal when said stick relay is energized, a holding circuit for said stick relay including a front contact of said track relay, and other manually controlled means for energizing said signal even though said holding circuit is opened by the passage of a train through said section.

73. In combination with a stretch of railway track containing a power operated track switch, a signal governing traffic over said switch, a circuit controller locatedadjacent said stretch and capable of assuming two positions, means controlled from a remote point for operating said circuit controller to one or the other of said positions, means requiring said circuit control-- ler to be in one position for actuating said power operated switch to normal or reverse, and means requiring said circuit controller to be in the other position for causing said signal to indicate proceed.

74. In combination with a stretch of railway track containing a power operated switch, a signal governing trafiic over said switch, a manually controlled circuit controller capable of assuming two positions, means requiring said circuit controller to be in one position for actuating said power operated switch to normal or reverse, means requiring said circuit controller to be in another position to clear said signal, and time measuring means for at times delaying the movement of said circuit controller to said other position.

'75. In a train dispatching system, means for controlling a railway switch .and a signal governing train movements over said switch from a remote oflice, approach locking means for preventing operation of said switch if a train enters an approach zone when the signal which said train is approaching indicates proceed but which will not prevent operation of said switch if a train enters such zone while said signal indicates stop, means for indicating at said office the presence of a train in said approach zone,'and for indicating the position of said signal.

76. In combination, a railway track switch, a signal for governing trafilc movements over said switch, a control circuit for said signal, a first stick relay, a manually controlled pick-up circuit for said first stick relay, a stick circuit for" said first stick relay controlled by said signal control circuit and by traffic conditions, a second stick relay, a pick-up circuit for said second stick relay controlled by traffic conditions by said first stick relay, a stick circuit for said second stick relay controlled by said first stick relay, and means controlled by said second stick relay for controlling said switch.

77. An electrical train indicating system comprising series of track circuits, an indicator circuit comprising a source of current and electrical resistance, and relays controlled by the track circuits and in turn controlling said electrical resistance to vary the amount thereof in said indicator circuit.

'78. In a system for determining the location of a railroad train, a stretch of track for the train divided into sections, a circuit electrically separated from said track, a device connected with said circuit for each section, each of said devices, when operated by a train in its section, automatically affecting the electrical characteristics of said circuit diiierently, and means in said circuit responsive to the changes of the electrical characteristics of said circuit.

79. In a system for determining the location of a railroad train, a stretch of track for the train divided into sections, a circuit insulated from said track, means connected to said circuit for each section controllable by a train in said section for changing the characteristics of said circuit, the means for adjacent sections, when controlled, being adapted to affect said circuit differently, and means in said circuit responsive to changes in said characteristics.

80. In a system for determining the location or" a railroad train, a stretch of track for the train divided into sections, a circuit electrically separated from said track, a source of energy in said circuit, means connected with said circuit for each section controllable by a train in said sec tion for changing the current in said circuit, the means for adjacent sections, when controlled, being adapted to change said current differently, and means in said circuit responsive to said current and said current as changed.

81. In a train dispatching system for railroads, a central ofilce and a distant station connected by line wires, a section of railway track at said station provided with a track circuit including a track relay, an indication relay at said oifice having two energized positions in addition to a normal deenergized position, means operating over said line wires for controlling said indication relay from said station and including means for momentarily operating the indication relay to one energized position when said track relay becomes deenergized and for momentarily operating the indication relay to the other energized position when said track relay becomes energized, two indication control circuits at said office including contacts closed when said indication relay occupies said two energized positions respectively, two visual indicators one for each said circuit and each arranged to be actuated when the associated circuit is closed and to remain actuated after the associated circuit is opened but to be restored to normal when the other circuit becomes closed, and a single stroke gong located at the office and operated momentarily when one of said indicators becomes actuated to call attention to the change in the condition of the track section at the station. 7

82. In a centralized trailic controlling system for railroads, a track section includinga track switch, a switch machine for operating said track switch, relay means for governing said switch machine, control means at a remote point for governing said relay means, means for preventing operation of the switch when said track section is occupied even though said control means is operated, a polarized indication circuit having current flowing in one direction with the track switch in one position and with said relay means in correspondence therewith and having current flowing in the opposite direction with the track switch in an opposite position and with said relay means inccrrespondence therewith but having no current therein when said relay means and. said track switch are out of correspondence, and indication means included in said indication circuit.

83. In a centralized trafiic controlling system for railroads, a track section including a track switch, a switch machine for operating said track switch, relay means for governing said switch machine, control means at a remote point for governing said relay means, means for preventing operation of the switch when said track section is occupied even though said control means is operated, a polarized indication circuit having current flowing in one direction with the track switch in one position and with said relay means in correspondence therewith and having current flowing in the opposite direction with the track switch in an opposite position and with said relay means in correspondence therewith but having no current therein when said relay means and said track switch are out of correspondence, indication means included in said indication circuit, and a signal controlled by said indication means.

84. In a centralized traffic controlling system for railroads, a track section including a track switch, a switch machine for operating said track switch, relay means for governing said switch machine, control means at a remote point for gov-' erning said relay means, means for'preventing operation of the switch when said track section is occupied even though said control means is up erated, a polarized indication circuit having current flowing in one direction with the track switch in one position and with said relay means in correspondence therewith and having current flowing in the opposite direction with the track switchin an opposite position and with said relay means in correspondence therewith but having no current therein when said relay means and said track switch are out of correspondence, indication means included in said indication circuit, and a signal at said remote point controlled by said indication means.

85. In combination, a railway track switch, a signal for governing traiiic movements over said switch, a control circuit for said signal, a stick relay, a pickup circuit for said relay-controlled by traffic conditions, a stick circuit for said relay controlled by said signal control circuit, and an indication means controlled by said relay.

86. In combination, a track switch of a railway system, a switch machine for'operating said switch, a signal associated with said switch for governing movement of traffic over said switch,

and a two-position contact whlch'ii in one p si tion closes a circuit for clearing said signal and when in the other position closes a circuit for controlling said switch machine, whereby said switch machine can not be operated unless said signal is at stop.

8'7. In combination, a track switch of a railway system, a switch machine for operating said switch, a plurality of signals associated with said switch for governing movement of traffic over said switch, and a two-position contact which if in one position closes a circuit for clearing any one of said signals and when in the other position closes a circuit for controlling said switch machine, whereby said switch machine can not be operated unless all of said signals are at stop.

88. In combination, a track switch of a railway system, a switch machine for operating said switch, a signal associated with said switch for governing movement of traffic over said-switch, a two-position contact which if in one position closes a circuit forcontrolling said signal to stop and when in the other position closes a circuit for controlling said switch machine, and timing means for delaying the movement of said contact to said other position, whereby said switch machine can not be operated until after a lapse of time after said signal has been put to stop.

89. In combination, a track switch of a railway system, a switch machine for operating said switch, a plurality of signals associated with said switch for governing movement of traflic over said switch, a two-position contact which if in one position closes a circuit for controlling any one of said signals to stop and when in the other position closes a circuit for controlling said switch machine, and timing means for delaying the movement of said contact to said other position, whereby said switch machine can not be operated until said signals have been at stop for a predetermined period of time.

90. In combination, a track switch, a switch machine for operating said track switch, a signal for governing movement of traffic over said track switch, a signal relay which if energized permits clearing of said signal, a switch machine relay for controlling said switch machine, two levers one for energizing said signal relay and the other for energizing said switch machine relay, and a contact in the control circuit of said switch machine relay closed only if said signal control relay is deenergized.

91. In combination with a railway signal capable of displaying either a first or a second indication, a control circuit for said signal including a resistance unit and a source of current, a manually operable device, means controlled by said manually operable device for at times forming a shunt path around said resistance unit in said circuit, means for causing said signal to display said first indication when said resistance unit is included in said circuit, means for causing said signal to display said second indication when said shunt path is formed around said resistance unit in said circuit, and means for causing said signal to continue to display said second indication after said shunt path has been opened.

92. In combination with a railway signal capable of displaying either a normal proceed indication'or a call-on indication, a home relay, a call-on relay responsive only to current of greater magnitude than that which is required for the operation of said home relay, a resistance unit, a circuit including said home and call-0n relays and said resistance unit in series, a manually operable contact bywhich a shunt path of low resistance can be closed around said resistance unit in said circuit, a source which while said shunt path is open supplies said circuit with current of sufiicient magnitude to operate said home relay but not said cal1-on relay, but which source while said shunt path is closed supplies said circuit with current of sufficient magnitude to operate said call-on relay as well as said home relay, means for controlling said normal proceed signal indication by said home relay, and means for controlling said call on signal indication by said call-on relay.

93. In a railway switch and signal control layout, the combination with a distant track switch, a signal associated with said track switch, a detector track circuit for said switch, a line circuit connecting a local dispatchers oflice and said layout for controlling said signal subject to traflic conditions ahead, an approach section separate from said detector track circuit, means for preventing operation of said track switch when said approach section is occupied unless it became occupied after said signal was put to stop, and means independent of said signal for indicating occupancy of said approach section over said line circuit.

94. In a railway switch and signal control layout, the combination with a distant track switch, a switch machine for controlling said switch, a signal associated with said track switch, a detector track circuit for said switch, a line circuit connecting a local dispatchers ofice and said layout for controlling said switch machine and controlling said signal subject to traffic conditions ahead, an approach section separate from said detector track circuit, means for preventing operation of said track switch when said approach section is occupied unless it became occupied after said signal was put to stop, and means independent of said signal for indicating occupancy of said approach section over said line circuit.

95. In combination, a plurality of electroresponsive devices, a manually operable device, a second manually operable device operated inde pendently of first manually operable device, a stick relay, a pick-up circuit for said stick relay controlled by said first manually operable device, a stick circuit for stick relay controlled by said second manually operable device, and means controlled by said stick relay for energizing said electroresponsive devices successively.

96. In combination, a circuit extending between two electroresponsive signal operating mechanisms respectively associated with the opposite ends of a section of railway track over which traffic is to move in either direction, a current source at each end the circuit for supplying current to said circuit but normally disconnected therefrom, a central office controlled relay associated with each end of the circuit, means governed by each central office controlled relay when energized to connect the associated current source with said circuit, and signals governed by mechanisms to permit trafiic to move through the section in a direction determined by the end at which said circuit is supplied with current.

97. In combination, a stretch of track, a signal at each end of said stretch for governing the movement of traffic into said stretch from that end, an electroresponsive mechanism associated with each of said signals which when energized causes the associated signal to indicate proceed, a relay manually controlled from a central ofiice associated with each of said signals, a movable contact on each of said relays, said movable contacts being connected by a partial circuit and said movable contacts if in one position connecting said partial circuit to the associated electroresponsive mechanism and if in another position connecting said partial circuit to a source of current, whereby'both of said mechanisms may be controlled over the same partial circuit and only one of said mechanisms may be energized at one time.

98. In combination, a railway track switch, a al for governing trafiic movements from a n direction over said switch, a second signal ior governing traffic movements from said given direction toward said first signal, an approach locking relay, a pickup and a stick circuit for said relay one of which is controlled by said first signal and the other of which is controlled by said second signal and by track conditions, and means controlled by said relay for controlling said switch.

99. In combination, a railway track switch, a signal for governing traflic movements from a given direction over said switch, a second signal for governing trafiic movements from said given direction toward said first signal, a locking relay, a pickup and a stick circuit for said relay one of which is controlled by said first signal and the other of which is controlled by said second signal,

and means controlled by said relay for controlling said switch.

100. In combination, a railway track switch, a signal for governing traific movements over said switch, a stick relay, a slow acting device having a normally open contact and a normally closed contact which remains open for a measured interval of time when said device is operatedto close said normally open contact, means controlled by said normally closed contact for controlling said signal, a pick-up circuit for said relay controlled by said normally open contact, a stick circuit for said relay controlled by said signal, and means controlled by said relay for controlling said switch.

101. In combination, means for controlling a switch machine in accordance with the polarity of current of a particular character transmitted wholly over a single line circuit from a source at a central office and for transmitting an, indication to said central ofiice by current or" the same character over said line circuit but from a source at said way station and having a polarity corresponding to the positon of said switch machine.

102. In a dispatching system of the type described, the combination with signals at the end of a passing siding governing traiiic in opposite directions in accordance with the position of the switch, two stick relays adjacent said switch governing said signals, one stick relay controlling the other, and means operable from a distant point for controlling said stick relays.

103. In a dispatching system of the type described, the combination with signals at the end of a passing siding governing trafiic in opposite directions in accordance with the position of the track switch, two stick relays governing said signals, one stick relay having a back contact included in the energizing circuit of the other stick relay, and means operable from a distant point for controlling said stick relay.

104. In combination, a traffic governing device having different control conditions, a normally deenergized relay for governing the operation of the device, a control circuit to energize said relay for causing an operation of the device, means effective upon the completion of an operation of the device to deenergize said relay, and indication means governed in accordance with the condition of the device and rendered ineiiective upon the release of said relay.

105. In combination, a stretch of railway track including a track switch, a polarized indication device, means controlled by said switch for supplying current of a given polarity to said device, and means controlled in accordance with track circuit conditions in said stretch for supplying current of the opposite polarity to said device.

106; In combination, a stretch of railway track including a track switch, a signal for governing traffic movements over said switch, a manually controlled signal control relay, means controlled by said signal control relay for controlling said signal, a switch locking relay having a pickup and a stick circuit one of which is controlled by said signal and by said signal control relay and the other of which is controlled by trafiic conditions in at least a portion of said stretch, and switch control means controlled by said locking relay for controlling said switch.

107. In combination, a stretch of railway track including a track switch, a signal for governing trafiic movements over said switch, a manually controlled signal control relay, means controlled by said signal control relay for controlling said signal, a manually controlled device, a switch locking relay having a pickup and a stick circuit one of which is controlled by said signal and by said signal control relay and the other of which is controlled by said manually controlled device, and switch control means controlled by said looking relay for controlling said switch.

108. In combination, a stretch of railway track including a track switch, a signal for governing traflic movements over said switch, a signal control relay, means including a front contact of said signal control relay for controlling said signal, a switch looking relay having a pickup and a stick circuit one of which is controlled by said signal and includes a back contact of said signal control relay and the other of which is controlled by traflic conditions in at least a portion of said stretch, and means controlled by said locking relay for controlling said switch.

109. In combination, a two-position relay, 9. slow pickup slow-release repeating relay controlled by said two-position relay, and means controlled jointly by said relays for briefly transmitting to a remote point one distinctive indication when said two-position relay picks up and a different distinctive indication when said two-position relay releases.

110. In combination, a section of railway track, a track relay for said section, a slow pickup slowrelease repeating relay controlled by a front contact of said track relay, an indication circuit including a front contact of said track relay and a back contact of said repeating relay, a second indication circuit including a back contact of said track relay and a front contact of said repeating relay, and means responsive to the momentary closing of said circuits for continuously indicating the condition of said track section.

111. A train dispatching system of the wayside signal indicating type comprising, a distant track switch, a power operated switch machine for operating said track switch, a control relay for controlling said switch machine, a simple line circuit for controlling said control relay from a local source of current at a local dispatchers office, and means for distinctively indicating by separate indicators the passage of a train over said switch and the approach of a train toward said switch over said line circuit.

112. In a train dispatching system, the combination with a line circuit connecting a dispatchers ofiice and a distant railway signal including a control relay connected in series in said line circuit at the signal end of said circuit and a manually operable lever having a contact connected in series with a source of current at the oflice end of said circuit, of another contact on said lever closed when said first-mentioned contact is open and which if closed includes an indicating relay in said circuit at the ofiice end of said circuit, means effective if there is a train approaching within a predetermined distance of said signal for including a source of current in said line circuit at said signal end of said circuit to energize said indicating relay, and an indicator controlled by said indicating relay.

HERBERT A. WALLACE. 

